<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>

    <style>

        .box{
            height: 100px;
            width: 100px;
            /* 浮动导致对后续元素产生影响 */
            float: left;
        }

        .box1{
            background-color: aqua;
        }
        .box2{
            background-color: blueviolet;
        }
        .box3{
            background-color: tomato;
        }
        .box4{
            height: 150px;
            width: 150px;
            background-color: yellow;
        }

    </style>
</head>
<body>
    <div class="box box1"></div>
    <div class="box box2"></div>
    <div class="box box3"></div>
    <div class="box4"></div>
</body>
</html>